The present application relates generally to a thermosetting adhesive used in adhering or bonding optical waveguides to form panels.
Optical waveguides have been used to develop panels that may be useful as optical display screens. The panel may be used for rear projection displays, such as those taught in U.S. Pat. Nos. 6,457,834 and 6,999,665, which are incorporated by reference herein. The panel may be used for front projection displays, such as those taught in U.S. Pat. Nos. 6,535,674, 6,741,779, and 7,116,873, which are incorporated by reference herein. Waveguides include a transmissive core bound by cladding where the index of refraction of the cladding is less than the index of refraction for the core. Typically, waveguides may be in the form of flat ribbons stacked vertically and extending continuously in the horizontal direction along the entire panel width.
Typical waveguides and the panels made from waveguides tend to degrade when exposed to extreme environmental conditions (e.g., rain, sun, extreme temperatures, pressures, and humidity or extreme changes in temperature, pressure, and humidity). Extreme environmental conditions may be experienced by panels used in airplanes (commercial or military), automobiles, or other outdoor or extreme environmental applications (i.e. movie theater screens, ATM machines screens, or televisions mounted outside). The cladding and the adhesive(s) used in typical waveguides are the likely cause of the degradation. Therefore, there is a need for an improved waveguide or optical structure incorporating a stronger adhesive so the waveguides or panel can withstand extreme environmental conditions.